Catalyst and method of catalyst manufacture

ABSTRACT

The catalyst of the invention is a particulate catalyst in the form of particles having a minimum dimension of at least 0.8 mm, including a transition metal or a compound thereof dispersed on a porous support material, characterised in that said catalyst particles comprise at least 35% w/w total transition metal; and the transition metal surface area of said catalyst is at least 110 m 2  per gram of transition metal and the tapped bulk density of a bed of the catalyst particles is at least 0.7 g/ml. The method of making a catalyst includes multiple steps of impregnation of a porous support with a metal ammine solution followed by drying, calcination and reduction of the dried material. The catalyst is useful in hydrogenation reactions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase application of PCTInternational Application No. PCT/GB2010/052203, filed Dec. 23, 2010,and claims priority of British Patent Application No. 1000045.3, filedJan. 4, 2010, the disclosures of both of which are incorporated hereinby reference in their entireties for all purposes.

FIELD OF THE INVENTION

The present invention relates to catalysts comprising one or moretransition metals dispersed on a porous support.

BACKGROUND OF THE INVENTION

Catalysts comprising metals and metal compounds dispersed on a poroussupport material have been well known and used in the chemicals industryfor many years, for a variety of purposes including hydrogenation,dehydrogenation of chemical feedstocks. U.S. Pat. No. 4,490,480describes such catalysts, useful for various hydrogenation reactions,which consist of 5 to 40% (w/w) of nickel upon a transition alumina, inparticular gamma alumina support. These catalysts have an active nickelsurface area of between 80 and 300, preferably 100-250 m²/g of nickeland the nickel crystallites have an average diameter of 1 to 5,preferably 1.5 to 3 nm. The nickel crystallites are dispersed for atleast 95% in the pores of the alumina. The patent describes a method ofmaking catalysts by heating an aqueous suspension or mixture of atransition alumina in a dissolved nickel ammine complex for some time toa temperature of 60-100° C., preferably 75-95° C., which causes theprecipitation of nickel hydroxide. The catalyst suspension is separatedoff and, if desired, washed, thereafter dried and calcined to nickeloxide and, if need be, reduced. Alternatively, alumina pellets orextrudates are impregnated with a concentrated solution of a nickelammine complex; subsequently nickel is precipitated by temperatureincrease.

U.S. Pat. No. 4,920,089 provides a nickel upon transition aluminacatalyst containing 5-40% w/w of nickel, with an active nickel surfacearea between 80 and 300 m²/g of Ni, with a transition alumina thatsatisfies a particular X-ray diffraction pattern. Preferably, the BETtotal surface area of the catalyst is between 50 and 200 m²/g catalystand is substantially free from pores with a radius below 2.0 nm. Thecatalysts were prepared by impregnating shaped theta-alumina particleswith an ammoniacal nickel solution having a particularly high pH value,namely between 9 and 11, and subsequently evaporating the impregnatedalumina particles to dryness, calcining and reducing.

The methods described in the above-mentioned prior art patents enablehighly disperse and active metal catalysts to be formed which have beenhighly successful. We have found, however, that it has not been possibleto prepare catalysts in the form of pellets or shaped forms suitable forfixed bed-type reactions which have a metal content greater than about33% w/w and which have a high metal dispersion coupled with a high crushstrength. It is an object of the invention to provide such a catalyst.

SUMMARY OF THE INVENTION

According to the invention we provide a particulate catalyst in the formof particles having a minimum dimension of at least 0.8 mm, comprising atransition metal or a compound thereof dispersed on a porous supportmaterial, characterised in that said catalyst particles comprise atleast 35% w/w total transition metal; and the transition metal surfacearea of said catalyst is at least 110 m² per gram of transition metaland the tapped bulk density of a bed of the catalyst particles is atleast 0.7 g/ml.

According to a second aspect of the invention, we provide a method formaking a catalyst comprising a transition metal or a compound thereofdispersed on a porous support material, said catalyst containing atleast 35% w/w of total transition metal, comprising the steps of:

-   -   a) providing a solution of an ammine complex of said transition        metal;    -   b) impregnating a porous support material in the form of        particles having a minimum dimension of at least 0.5 mm and        wherein the total pore volume is greater than 1.0 ml/g with said        solution of ammine complex;    -   c) drying the impregnated support particles resulting from step        (b);    -   d) repeating steps (b) and (c) at least four more times until        the amount of transition metal in the particle is of the        required level, and including a step of    -   e) calcining the dried impregnated support particles from        step (c) at a temperature and duration sufficient to convert at        least a majority of the transition metal compounds in the        support to transition metal oxides;    -   f) optionally reducing at least 50% of the remaining transition        metal compound and transition metal oxide to elemental metal.

The transition metal is preferably selected from cobalt, nickel orcopper and may comprise more than one transition metal.

BRIEF DESCRIPTION OF THE DRAWING

The invention is further described by reference to the following Figuresin which:

FIG. 1 is a plot of conversion vs. feed processed using the catalysts ofComparative Example 1, Example 2, and Comparative Example 3.

DETAILED DESCRIPTION OF THE INVENTION

The catalysts of the invention are particularly useful in hydrogenationreactions, i.e. for hydrogenating hydrogenatable organic compoundsincluding unsaturation in olefinic or aromatic compounds and functionalgroups including carbonyl compounds, nitro-groups, nitriles andhydrogenolysis of esters. The catalysts may be particularly useful inthe dearomatisation of solvents, for example.

The total transition metal in the particulate catalyst is at least 35%w/w. Total transition metal means the mass of metal whether present aselemental reduced metal or as a metal compound, expressed as apercentage of the total catalyst mass. The amount of metal may bemeasured by X-ray fluorescence (XRF) or inductively coupled plasmaatomic emission spectrometry (ICP-AES). For the purposes of determiningthe total metal content of the catalysts described and claimed herein,we use ICP-AES, using a copper sulphate internal standard and calibratedusing standard nickel sulphate solutions. Both methods are well knownfor use in determining metal content of materials such as catalysts andthe skilled person will have such methods available to him.

The tapped bulk density of the catalyst is at least 0.7 g/ml whenmeasured using the following method. A 100 g (approximately) sample ofcatalyst particles is accurately weighed into a standard 250 mlmeasuring cylinder, placed on the platform of an automated tapped bulkdensity analyser and tapped 2000 times before measuring the volume ofthe sample. The bulk density is then calculated as the accurate weightof the catalyst in grams divided by the volume of the sample aftertapping. The bulk densities recorded in this document are measured usinga Quantachrome Dual Autotap™ instrument, available from QuantachromeInstruments. Preferably the tapped bulk density of the catalystparticles is at least 0.75 g/ml.

Although catalysts containing 35% of nickel and having relatively highnickel metal surface areas are known in the form of powders and fineparticles, we believe that such catalysts in the form of particleshaving a minimum dimension of at least 0.8 mm and a tapped bulk densityof at least 0.7 are new. Particles having a minimum dimension of atleast 0.8 mm include formed catalyst shapes such as spheres, cylinders,lobed cylinders (i.e. shapes having a transverse cross-section in theshape of a multi-lobed circle such as trilobes, quadrolobes orpentalobes), wheels, rings, saddles and other known shapes. Some shapesmay include channels, recesses or holes. The minimum dimension may bethe diameter or length as appropriate. Preferably the minimum dimensionis at least 1 mm. Normally the catalyst particles are measured and anaverage minimum dimension is established. The minimum dimension figuresused in this document is calculated as an average of the measuredminimum dimension of 40 catalyst particles.

The particles may be formed by granulation, tabletting, extrusion orother known methods. Extruded particles are preferred. In a preferredembodiment of the invention the catalyst particles comprise extrudedcylinders or lobed cylinders. Such particles are suitable for use infixed bed reactors, wherein a feed compound or mixture of compounds iscaused to flow over and/or through a bed of catalyst particles. For usein a catalyst bed it is necessary that the catalyst particles aresufficiently strong to remain intact within the bed. Preferably thecatalyst particles have a crush strength of at least 10 N/mm, morepreferably at least 12 N/mm, expressed as the average crush strength of25 particles. The crush strength of 25 particles is measured using anEngineering Systems CT5, ½ tonne crush test machine. The average crushstrength per unit length is then calculated from the average forcedivided by the average length of the particles. The particles are heatedto 500° C. in a nickel crucible for one hour prior to testing and thenmaintained at 1000C. to avoid absorption of moisture.

The porous support material is preferably a transition alumina. Thetransition alumina may include delta, eta, gamma and/or theta aluminas.One preferred embodiment uses a transition alumina comprising mainlygamma-phase alumina. The support material is generally in the form ofshaped, e.g. extruded, particles as described above for the catalyst.The porous support material preferably has a total pore volume, asmeasured by mercury intrusion, of at least 1.0 ml/g. The porous supportmaterial preferably has a total surface area, as measured by BETmethods, of at least 250 m²/g. A particularly preferred porous supportmaterial is a transition alumina support having a pore volume of atleast 1.0 ml/g and a bimodal pore size distribution. We have found thatusing a catalyst support of this type, it is possible to introduce agreater amount of the transition metal into the support material than ina support having a unimodal pore size distribution, while retainingsufficient crush strength for the catalyst to be used in a fixed bed. Apreferred catalyst support has a pore size distribution, as measured bymercury porosimetry, in which at least 20% (more preferably at least25%) of the total pore volume is contained in pores having a diameter offrom 100 nm-700 nm and at least 30%, more preferably at least 40%, ofthe total pore volume is contained in pores having a diameter of from 5nm-20 nm.

A transition metal ammine complex for use in preparing the catalystsaccording to the method of the invention may be made by dissolving atransition metal compound or a quantity of the transition metal inmetallic form, in a solution of an ammonium compound, such as ammoniumcarbonate, in ammonium hydroxide. Transition metal ammine carbonatecomplexes are preferred but other anions may be used, such as sulphates,acetates or formates.

A cobalt ammine complex is most preferably a cobalt ammine carbonatecomplex which is formed in situ in aqueous solution by dissolving basiccobalt carbonate in a solution of ammonium carbonate in aqueous ammoniumhydroxide, to give a product of the desired cobalt content.Alternatively other cobalt salts may be used, including organic saltssuch as cobalt acetate or cobalt formate. Nickel and copper amminecarbonate solutions may be prepared in a similar manner.

A cobalt ammine carbonate complex is the product of dissolving basiccobalt carbonate, preferably of empirical formulaCo(OH)_(2-2x)(CO₃)_(x), wherein 0≦x≦1, in a solution of ammoniumcarbonate in aqueous ammonium hydroxide, to give a product of thedesired cobalt content. The cobalt ammine carbonate solution may be madeby dissolving basic cobalt carbonate in an aqueous solution of ammoniumcarbonate or ammonium carbamate containing additional ammoniumhydroxide. The relative amounts should be such that the pH of thesolution is in the range 7.5 to 12, preferably 9 to 12. The solutionpreferably contains 0.1 to 2.5 moles of the cobalt complex per litre. Asthe concentration of cobalt increases, then generally the proportion ofcarbonate ions relative to hydroxide ions in the basic cobalt carbonatefeed should be increased. Additional ammonium hydroxide solution may beadded if required to reduce the viscosity of the solution. As analternative, the cobalt ammine carbonate solution may be made bydissolving metallic cobalt, preferably in powdered form, in aqueousammonia of pH 11-12, in the presence of oxygen or air, either withaddition of ammonium carbonate or with addition of CO₂ gas. A cobaltammine complex solution may be allowed to oxidise before beingimpregnated into the catalyst support, either by aging in contact withan oxygen-rich gas or by chemical or electrochemical oxidation in orderthat the Co(II) complex is converted, at least in part, to a Co(III)complex.

When the transition metal is nickel, the catalysts may be made byimpregnating the porous support with the appropriate amount of anaqueous solution of a nickel ammine complex. A nickel ammine carbonatecomplex may be made by dissolving basic nickel carbonate in a solutionof ammonium carbonate in aqueous ammonium hydroxide, to give a productof the desired nickel content. The solution of the nickel ammine complexpreferably has a pH in the range 9 to 10.5.

A copper ammine carbonate solution may be made by dissolving basiccopper carbonate in an aqueous solution of ammonium carbonate containingadditional ammonium hydroxide. The relative amounts should be such thatthe pH of the solution is in the range 7-12, preferably 8-11. Thesolution preferably contains 2-5, particularly 2-4, moles of the coppercomplex per litre. As the concentration of copper increases, thengenerally the proportion of carbonate ions relative to hydroxide ions inthe basic copper carbonate feed should be increased.

Preferably, the total number of impregnation steps (b) is at least five,more preferably at least six and the impregnated catalyst resulting fromeach step (b) is then dried in step (c). In a preferred method, steps(b) and (c) are carried out three times and then step (e) is carried outand then steps (b) and (c) are carried out at least once more (morepreferably at least twice more, especially three times more) and thencalcination step (e) is carried out a second time. Preferably,substantially all the transition metal compounds are converted totransition metal oxides in step (e).

Preferably, the calcined catalyst from the final calcination step (e) isreduced in a hydrogen-containing gas. Preferably the reduced catalyst isthen passivated using an oxygen containing gas, using conventionalcatalyst passivation methods, such that the catalyst temperature doesnot exceed 100° C. when exposed to air. Proper passivation of thecatalyst allows it to be stored and handled in air without catching firedue to the pyrophoric nature of finely divided metal particles, as iswell known.

The dried impregnated support particles are calcined according to step(e) of the method, preferably following at least every threeimpregnation and drying steps. Preferably a calcination step is carriedout when the amount of transition metal in the particle has, by means ofsufficient successive impregnation steps, reached the required level.

The transition metal surface area of the catalyst is at least 110 m² pergram of transition metal. The surface area of the transition metal ismeasured following reduction of the metal to its elemental state. Whenthe transition metal is nickel, the nickel metal surface area is atleast 110 m² per gram of total nickel present in the catalyst asmeasured by hydrogen chemisorption after the catalyst has been reducedin flowing hydrogen at a pre-determined reduction temperature for onehour. The reduction step is a part of the surface area measurementprocedure and is done in order to reduce the nickel compounds toelemental nickel for measurement of hydrogen chemisorption.

When the nickel in the catalyst is substantially or wholly in the formof oxidic nickel compounds, the pre-determined reduction temperature is430° C. When the nickel in the catalyst is largely or substantially inelemental form, i.e. when the catalyst has been pre-reduced andpassivated then the pre-determined reduction temperature is 240° C.0.7-0.8 g of sample is accurately weighed and transferred to the samplecell of a chemisorption apparatus. The hydrogen flow through the samplecell is set to 250 cm³min⁻¹. The temperature is then raised at a ramprate of 3°C. min⁻¹ to the selected reduction temperature and heldconstant for one hour. Following reduction the H₂ flow is stopped andthe sample cell is outgassed at 450° C. under vacuum for six hours, andthen allowed to cool to 50° C. while maintaining the vacuum.Chemisorption of H₂ is carried out over a range of pressures between 100and 760 torr. The sample is allowed to equilibrate at each pressure for60 seconds at each pressure. The volume of hydrogen chemisorbed at eachpressure is plotted against pressure. The best linear portion of theisotherm is chosen and extrapolated back to zero pressure intercept todetermine the monolayer capacity. The monolayer amount is the capacitydivided by the sample weight in grams.

The specific nickel surface area is determined from the followingequation:

S_(Ni)=[Nm×NA×S]/D

Where: S_(Ni)=specific nickel surface area, m²g-1

Nm=monolayer amount, mol g⁻¹

NA=Avogadro constant, 6×10²³ mol⁻¹

S=stoichiometry of H₂ adsorption which is taken to be 2

D=surface density of Nickel atoms, 1.54×10¹⁹ atoms m².

Preferably the nickel metal surface area is at least 120 m²/g.

The cobalt surface area is determined by H₂ chemisorption. This methodis used when a cobalt surface area measurement is mentioned in thisspecification for the catalysts of the invention containing cobalt asthe transition metal (unless otherwise specified). Approximately 0.2 to0.5 g of sample material is firstly degassed and dried by heating to140° C. at 10° C./min in flowing helium and maintaining at 140° C. for60 minutes. The degassed and dried sample is then reduced by heating itfrom 140° C. to 425° C. at a rate of 3° C./min under a 50 ml/min flow ofhydrogen and then maintaining the hydrogen flow at 425° C. for 6 hours.Following this reduction, the sample is heated under vacuum to 450° C.at 10° C./min and held under these conditions for 2 hours. The sample isthen cooled to 150° C. and maintained for a further 30 minutes undervacuum. The chemisorption analysis is then carried out at 150° C. usingpure hydrogen gas. An automatic analysis program is used to measure afull isotherm over the range 100 mm Hg up to 760 mm Hg pressure ofhydrogen. The analysis is carried out twice; the first measures the“total” hydrogen uptake (i.e. includes chemisorbed hydrogen andphysisorbed hydrogen) and immediately following the first analysis thesample is put under vacuum (<5 mm Hg) for 30 minutes. The analysis isthen repeated to measure the physisorbed uptake. A linear regression isthen applied to the “total” uptake data with extrapolation back to zeropressure to calculate the volume of gas chemisorbed (V).

Cobalt surface areas are calculated in all cases using the followingequation;

Co surface area=(6.023×1023×V×SF×A)/22414

where

V=uptake of H₂ in ml/g

SF=Stoichiometry factor (assumed 2 for H₂ chemisorption on Co)

A=area occupied by one atom of cobalt (assumed 0.0662 nm²)

This equation is described in the Operators Manual for the MicromereticsASAP 2010 Chemi System V 2.01, Appendix C, Part No. 201-42808-01,October 1996.

The copper surface area is conveniently determined by the nitrous oxidedecomposition method, for example as described by Evans et al in“Applied Catalysis”, 7, (1983), pages 75-83-a particularly suitabletechnique is described in EP 0 202 824. The methods are based on thedecomposition of a nitrous oxide molecule on a copper surface which isaccompanied by the liberation of one nitrogen molecule. In the followingequation, the subscript s indicates surface atoms.

N₂O (gas)+2 Cu_(s)→N₂(gas)+(Cu—O—Cu)_(s)

Reduction of the samples is carried out prior to copper surface areadetermination by heating the sample at a rate of 200 K/h in a current ofhydrogen diluted with argon (67% H₂/33% Ar by volume) to a temperatureof 393 K (120° C.) maintaining at this temperature for 30 min, thenincreasing the temperature at a rate of 100 K/h to the desired reductiontemperature, and maintaining at that desired temperature for 1 h. Afterreduction, the sample is cooled to 90° C. at which temperature thenitrous oxide decomposition is effected using a mixture of nitrous oxideand argon (1% N₂O/99% Ar by volume). It is assumed that the adsorptionstoichiometry of Cu_(s)/O_(ads) was 2 and that the area occupied by onecopper atom is 5.18 Å², i.e. at a 73% packing density, 1.46×1019 surfacecopper atoms per m².

EXAMPLES

The invention is further illustrated by reference to the followingExamples.

Comparative Example 1

250 g of ammonium carbonate was dissolved in 1 l of 33% aqueous ammoniasolution by stirring for 3 hours. 350 g of basic nickel carbonate wasthen added to the ammonium carbonate solution in 50 g portions, stirringfor 30 minutes after each addition. The resulting nickel hexamminesolution is stored until required.

The support used was an extruded transition alumina (theta/delta)catalyst support, in the form of trilobes having a nominal diameter of1.2 mm, average length of 2.9 mm and having a pore volume of 0.67 ml/g,a unimodal pore size distribution and a BET surface area of 110 m²/g.100 g of the support was placed in a beaker and sufficient of the nickelhexamine solution was added to cover the catalyst pellets and to keepthem covered during a soaking time of 2 minutes. The excess solution wasthen filtered off under water pressure and the wet pellets were dried at150° C. in a rotary calcination tube for 30 minutes under flowing air.The nickel hexamine complex decomposes during this drying stage with theevolution of ammonia to produce “green” nickel hydroxycarbonatedispersed in the pores of the support. The impregnation and drying wasrepeated twice more and the product was then calcined in air at 280° C.for 45 minutes to convert the nickel hydroxycarbonate to nickel oxide.The catalyst was then reduced in flowing hydrogen while heating to 450°C. to achieve a final degree of reduction of at least 90%. Followingreduction, the catalyst was passivated in a controlled nitrogen/oxygenmixture until stable in air. The nickel content was 21% and the Ni metalspecific surface area was 140 m²/g. The tapped bulk density was 0.73.

Example 2 Preparation of Catalyst According to the Invention

A nickel hexamine carbonate solution was prepared as described inComparative Example 1. the support used was a transition alumina 1.2 mmdiameter extruded trilobe having a BET surface area of 265 m²/g. Thepore volume was 1.1 ml/g and the pore size distribution was bimodal.

100 g of support was impregnated with nickel hexamine solution bysoaking and drying three times followed by calcination as described forcomparative Example 1. The resulting catalyst was then soaked a furtherthree times, each soaking step being followed by a drying step asbefore. After the last drying step, the product was calcined, reduced,and passivated. The nickel content was found to be 39%, and the nickelmetal specific surface area was 120 m²/g. The tapped bulk density was0.86. The crush strength was 22 N/mm.

Comparative Example 3

A catalyst was prepared as described in Comparative Example 1, exceptthat following the calcination step, the calcined material wasimpregnated and dried an additional three times. The material was thencalcined once more and then reduced and passivated following the sameprocedure as described in Comparative Example 1. The total nickelcontent was 30.2% and the Ni metal specific surface area was 121 m²/g.The tapped bulk density was 0.89.

Catalyst Activity Test

The sample is tested as whole particles in a down-flow, fixed-bedreactor (22.22 mm I.D.). The catalyst is tested in the form of wholeparticles. The catalyst particles (50 cm³) are mixed with 24 g ofsilicon carbide to form a catalyst bed and the reactor also included abed of silicon carbide at each end of the catalyst bed. The catalyst isactivated by heating slowly at 1/minute in hydrogen flowing at 50 l/hr(1 BarG pressure) to 120° C., holding the temperature steady for onehour and than raising the temperature at 2°/minute to 230° C. thenmaintaining that temperature for one hour. The catalyst is then cooledto room temperature while maintaining the flow of hydrogen. The test wasconducted at 30 BarG hydrogen pressure, 200° C. bed temperature and aLHSV of 4.5 h⁻¹. The feedstock used was Varsol™ 120 from Exxon, which isa naptha solvent, doped with benzothiophene to bring the S content to 24ppm. The feed contained approximately 30% aromatics. The H₂/feed ratioused was 89. The test is run until 6 kg of feedstock have passed acrossthe catalyst. The liquid product is sampled at intervals over thereaction time and analysed by multiwave UV for aromatics. The conversion(%) for each sample is obtained from the following:

Conversion (%)=[(AIN−AOUT)/AIN]×100

Where:

AIN=Aromatics In

AOUT=Aromatics Out

A plot of conversion against feed processed is constructed, using linearregression to obtain the best fit line. FIG. 1 shows the plots ofresults using the catalysts made in Comparative Example 1, Example 2 andComparative Example 3. The graph shows that the catalyst of Example 2has a higher activity throughout the duration of the test than thecatalyst of Comparative Example 1 and maintains a high activity over alonger period than the catalyst of Comparative Example 3. The catalystof Comparative Example 3 was made using the same method as the catalystof Example 2, but the amount of nickel in the finished catalyst wasconsiderably less. Without wishing to be bound by theory, we believethat the greater pore volume of the support used to make the catalyst ofExample 2 allows more nickel to be absorbed into the pore structure ofthe catalyst support.

1. A particulate catalyst in the form of particles having a minimumdimension of at least 0.8 mm, comprising a transition metal or acompound thereof dispersed on a porous support material, wherein saidcatalyst particles comprise at least 35% w/w total transition metal; andthe transition metal surface area of said catalyst is at least 110 m²per gram of transition metal and the tapped bulk density of a bed of thecatalyst particles is at least 0.7 g/ml.
 2. A catalyst according toclaim 1, n wherein the porous support comprises a transition alumina. 3.A catalyst according to claim 1, wherein the porous support material hasa bimodal pore size distribution.
 4. A catalyst according to claim 3,wherein the porous support material has a pore size distribution, asmeasured by mercury porosimetry, in which at least 20% of the total porevolume is contained in pores having a diameter of from 100 nm-700 nm andat least 30% of the total pore volume is contained in pores having adiameter of from 5 nm-20 nm
 5. A catalyst according to claim 1, whereinthe porous support material has a pore volume of at least 1.0 ml/g.
 6. Acatalyst according to claim 1, wherein the porous support is in the formof extruded cylinders or lobed cylinders.
 7. A catalyst according toclaim 1, wherein the transition metal is selected from cobalt, nickel orcopper and may comprise more than one transition metal.
 8. A catalystaccording to claim 1, wherein the transition metal comprises nickel. 9.A catalyst according to claim 1, wherein the metal surface area of saidcatalyst is at least 120 m² per gram of transition metal.
 10. A methodfor making a catalyst comprising a transition metal or a compoundthereof dispersed on a porous support material said catalyst containingat least 35% w/w of total transition metal, comprising the steps of: a)providing a solution of an ammine complex of said transition metal b)impregnating a porous support material in the form of particles having aminimum dimension of at least 0.8 mm and wherein the total pore volumeis greater than 1.0 ml/g with said solution of ammine complex; c) dryingthe impregnated support particles resulting from step (b) d) repeatingsteps (b) and (c) at least four more times until the amount oftransition metal in the particle is of the required level, and includinga step of e) calcining the dried impregnated support particles from step(c) at a temperature and duration sufficient to convert at least amajority of the transition metal compounds impregnated in the support totransition metal oxides; f) optionally reducing at least 50% of theremaining transition metal compound and transition metal oxide toelemental metal.
 11. A method as claimed in claim 10, wherein saidsolution of an ammine complex is a nickel ammine carbonate solution. 12.A method as claimed in claim 10, wherein steps (b) and (c) are carriedout three times and then step (e) is carried out and then steps (b) and(c) are carried out three times more and then step (e) is carried out asecond time.
 13. A method as claimed in claim 10, wherein the calcinedcatalyst from the final step (e) is reduced in a hydrogen-containing gasand then passivated using an oxygen containing gas such that thecatalyst temperature does not exceed 100° C. when exposed to air.
 14. Amethod of carrying out the hydrogenation of a hydrogenatable organiccompound by contacting said hydrogenatable organic compound with ahydrogen-containing gas, characterised that said contact is carried outin the presence of a particulate catalyst according to claim
 1. 15. Amethod of carrying out the hydrogenation of a hydrogenatable organiccompound by contacting said hydrogenatable organic compound with ahydrogen-containing gas, characterised that said contact is carried outin the presence of a particulate catalyst made according to the methodof claim 10.